Aeneid some structural observations:

• Structure of Aeneid
  
• Clearly indebted to Homer's Iliad and Odyssey, which characterize two halves of the poem.
  
• 1st half parallels Odyssey: quest for a home. 
• While Odysseus seeks to re-establish a previous normalcy, Aeneas seeks to establish a new normalcy.
  
• 2nd half parallels Iliad: a poem of war.
• While Aeneas lost the war in Troy, Aeneas wins (spoiler) in Italy.
• But it also divides neatly three ways
• 1-4: queen Dido and the story of the fall of Troy: setting is Carthage
  
• 5-8: arrival in Italy, visit to underworld, details of destiny
• 9-12 war and victory
• And it also divides emotionally by alternating books:
• 2,4,6,8,10,12 are emotionally peaky
  
• 1,3,5,7,9,11 are emotionally more quiet.
• And the first part divides environmentally:
• at sea:
  
• 1 (storm),
  
• 3 (wanderings),
  
• 5 (begins and ends at sea)
  
• onland
• 2 (fall of Troy),
  
• 4 (deception of Dido),
  
• 6 (arrival in Italy: underworld)